A new radio acoustic sounding system (RASS) for probing fog

To develop a combined acoustic and electromagnetic instrument, a RASS, that operates in the 2.4 to 3.0 GHz band and is able to resolve the temperature structure in the lowest 150 m of the nocturnal boundary layer. This instrument will then be utilized in an investigation of methods for predicting local fog formation and clearance.

Description of Work:

We have a RASS that operates at a radio frequency of 1.275 GHz. The initial part of this project would be to use this as the basis of a “mini” RASS that operates at approximately twice the frequency, hence has double the spatial and temporal resolution, of the present instrument.

Once the developed and tested we could use the temperature and wind profiles from the RASS and a high frequency sonar to test a range of models for fog formation and clearance. Earlier work suggests that a dynamical onedimensional model may be useful for “now casting” fog clearance.